U.S. Pat. No. 4,467,211--issued Aug. 21, 1984 for a "Method and Apparatus for Exposing Multi-Level Registered Patterns Interchangeably Between Stations of a Multi-Station Electron Beam Array Lithography System"--Donald O. Smith and Kenneth J. Harte, inventors and assigned to Control Data Corporation, discloses an electron beam array lithography system (EBAL) to which this invention relates. U.S. Pat. No. 4,467,211, the disclosure of which hereby is incorporated in its entirety into the disclosure of this application, in the description appearing in columns 11 and 12, relating to FIGS. 5A and 5B, explains certain of the rudiments of height-effect on the electron beam of an EBAL system. The description, however, does not include a comprehensive disclosure of how to best measure and correct for height effects during operation of the system. The present disclosure describes a preferred, two LFG position height measurement and correction method for obtaining the necessary height correction values for modifying the C and D coefficients set forth in equations (1) and (2) in column 8 of U.S. Pat. No. 4,467,211 to thereby obtain corrected G and H coefficients set forth in equations (7) and (8) in column 11 for deriving appropriately corrected deflection signals for application to the EBAL system as described in the patent.